Buick Encore Coolant Flush Procedure

DanVB1

New member
16
7
3
Buick Ownership
Encore
Below is a procedure I used to drain and flush the cooling system on an Encore. It’s pretty simple and easy and can be done by just about anybody with some mechanical ability.

  1. Lower the large bottom plastic shield by removing 3-4 screws (passenger side) and a couple of plastic clips (it can be left dangling in place, but don’t drive the car like this). There are two tabs on this shield which fit into the smaller shield in front of it, the large one can easily be pulled back. This will expose the bottom of the radiator.
  2. There is a drain petcock at the bottom the passenger side radiator with a short drain nipple. Attach a 12-18” hose to this nipple, the other end into a pan so that draining won’t be a mess. Open the thumbscrew to start the drainage flow. About 3-3.5 quarts will come out.
  3. Close the petcock and refill the cooling system with distilled water. I measured the amount of coolant drained in a painter’s pail; you should put back roughly the same amount of distilled water in the radiator expansion tank. When the tank is full of water, carefully open the burp valve above the top hose on the radiator (driver’s side) to purge trapped air out of the radiator.
  4. Start the engine, turn the AC to heat to purge the heater core of coolant and run the car until it’s at normal operating temperature. Pay close attention to the water level in the expansion tank, add distilled water to the tank if necessary, to maintain proper level.
  5. Let the engine cool a bit (45 minutes or longer, depending on ambient temperature), then drain again. Repeat another 2-3 times or so, this will get the vast majority of coolant out of the cooling system (I did 3 water flushes total).
  6. After you are satisfied with the flush process (the last water drained should be relatively clear), repeat the same procedure with pure concentrated coolant from the bottle. Maintain a concentration of 50% or a bit more, the cooling system should take at least one full gallon of concentrated DEXCOOL coolant. If you want, check the coolant concentration with a tester.
  7. Run the car, drive around the block and check the expansion tank level. Add coolant if necessary. Check again after overnight cool. Check for leaks. That’s it!

Notes:

Many radiator petcocks or burp valves have stops to prevent the plug from fully unscrewing. This car I don’t really know. Regardless, don’t try to remove the two plugs, just in case, only loosen them a bit until you can see liquid flowing from the petcock and there should be a drip or very small stream coming from the burp valve draining down the side of the radiator. You don’t want to lose the burp valve plug in particular. Also, don’t overtighten (they should only be snug), these plugs are plastic!

Sorry I didn’t post more pics, it didn’t cross my mind when doing this.



[ATTACH type="full" align="right" alt="Text Box: Location of Petcock Passenger Side

"]28018[/ATTACH]​
[ATTACH type="full" align="left" alt="Text Box: Burp Valve
Driver Side
"]28017[/ATTACH]
View attachment 28016 View attachment 28015
 
Last edited:

mitchflorida

Active Member
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South Florida
Buick Ownership
2016 Summit White Regal, Premium II, Moonroof, Driver Confidence Package
I just paid the mechanic $60 for him to do it for me. It does seem to take a lot of time and effort to do it yourself.
 

DanVB1

New member
16
7
3
Buick Ownership
Encore
I just paid the mechanic $60 for him to do it for me. It does seem to take a lot of time and effort to do it yourself.
The key is how many times the system is flushed with distilled water to get most of the old coolant out. It's a time consuming process and I doubt any commercial outfit will take the time to do it right.
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DanVB1

New member
16
7
3
Buick Ownership
Encore
Had a few free oil changes when we bought our certified used Encore.
The dummy who changed the last free one over tightened the plug and rounded the head. It took me over 4 hours to get it off trying many different techniques. See my post on how I removed the plug.
I believe the Buick dealer is the only is the place to find the plug. I tried all of the auto parts stores and the catalogs said they had the right plug, but they didn't match up side-by-side.
 
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